Extraction and identification of essential oil components of five Eucalyptus species in warm zones of Iran

The fresh leaves of five cultivated Eucalyptus species, i.e. Eucalyptus stricklandii Maiden, E. brockwayii, E. sargentii Maiden, E. largiflorens F. Muelland E. kruseana F. Muell were collected in the spring from Shushtar in Khuzestan province (South region of Iran). After drying the plant materials in shade, their essential oils were obtained by hydro-distillation. The oils were analyzed by GC and GC/MS. Seventeen components were identified in the oil of E. stricklandii with 1,8-cineole (71.2%) and α-pinene (9.2%) as the main constituents. Twenty-five compounds were identified in the oil of E. brockwayii with 1,8-cineole (17.8 %), isopentyl isovalerate (17.2%), α-pinene (14.0%), trans-pinocarveole (12%), β-pinene(7.5%) and ρ-cymene (5.3%) as major components. Sixteen compounds were characterized in the oil of E. sargentii with 1,8-cineole (56.7%), β-eudesmol (6.0%) and α-pinene (4.9%) as the main constituents. Fifteen components were identified in the oil of E. largiflorens with 1,8-cineole (41.3%), spathulenol (11.6%) and virdiflorol (15.9%) as major components. Fifteen components were identified in the oil of E. kruseana with 1,8-cineole (63.3%) and α-pinene (15.9%) as the main constituents. The results showed, although 1,8-cineole was the main component of the essential oils of all the studied Eucalyptus species, its relative content was higher in the oil of E. stricklandii.